Hot air blower



July 20, 1965 M, UMANN 3,196,250

HOT AIR BLOWER Filed Jan. 51, 1964 FIG: 6

1N VENTOR.

/722e M U 4/v/v United States Patent 3,196,250 HOT AIR BLOWER Harry M. Umann, Los Angeles, Calif., assignor, by mesne assignments, to Croname, Incorporated, Chicago, IlL, a corporation of Illinois Filed Jan. 31, 1964, Ser. No. 341,793 1 Claim. (Cl. 219-371) This invention relates to hot air blowers, and included in the objects of this invention are:

First, to provide a hot air blower which incorporates a novel means wherein air is caused to enter the blower through a radially inward and confined path across a heater coil to effect highly eflicient transfer of heat from the coil to the air.

Second, to provide a hot air blower, which due to efiicient transfer of heat to the air from the electric heating coil and due to an arrangement whereby a blanket of cooler air is maintained adjacent the wall surfaces confronting the heating coil, the blower housing and the wall surfaces of which, although exposed to heat, may be formed of inexpensive, easily molded, plastic material that would be damaged by excessive heat.

With the above and other objects in View, as may appear hereinafter, reference is directed to the accompanying drawings in which:

FIG. 1 is a side view of the hot air blower;

FIG. 2 is a fragmentary, longitudinal, sectional view taken through 2-2 of FIG. 1;

FIG. 3 is a transverse, sectional view taken through 3-3 of FIG. 1.

The hot air blower includes a blower housing 1 formed of complementary members having confronting ends provided with bosses 2 which receive screws 3 for securing the two members together. The blower housing 1 is provided with an axially directed inlet 4 having curved marginal walls 5. The housing 1 is also provided with a tangentially directed outlet 6.

Rotatably mounted within the housing 1 is a blower 7, preferably of the squirrel-cage type, which draws air axially inward through the inlet 4 and discharges the air tangentially from the outlet 6. The blower 7 is supported on a shaft 8 which extends axially through the opposite end of the housing 1 from the inlet 4. A motor 9 supported on yieldable pads 10, extending from the housing 1, drives the shaft 8.

The inlet end of the housing 1 is provided with axially outward directed posts 11. Three such posts are illustrated and are located near the periphery of the blower housing 1. The extremities of the posts support a plate 12 which is secured thereto by screws 13.

The plate 12 is provided with a central boss 14 having concave walls 15, which are approximately concentric with the curved marginal walls of the inlet 4. The marginal portion of the plate 12 beyond the diameter of the inlet 4 forms, with the confronting side of the blower housing 1, an annular passageway 16 for radially inward flow of air. This passageway merges into an annular transition passageway 17 formed between the marginal walls 5 and the concave walls 15.

The plate 12 is provided with heating element supports 18, three being illustrated, and a pair of terminals 19. A heating element 20 extends from one terminal around the supports 18 to the other terminal to form an essentially square figure disposed in the annular passageway 16.

The heating element 20 occupies a substantial portion of the passageway 16 so that air flowing radially inward through the passageway 16 traverses the heating element 20 and is heated thereby. The air which passes through the heating element 20 is blanketed by air flowing con tiguous to the housing 1 and contiguous to the plate 12 so that a minimum amount of heat is transferred to the housing 1 and the plate 12; consequently, the housing and plate may be formed of relatively inexpensive plastic material which would not stand excessive heat.

While a particular embodiment of this invention has been shown and described, it is not intended to limit the same to the exact details of the construction set forth, and it embraces such changes, modifications, and equivalents of the parts and their formation and arrangement as come within the purview of the appended claim.

What is claimed is:

A hot air blower, comprising:

(a) a blower housing having an axially directed circular inlet, the margins of said inlet being curved inwardly, said housing also having a tangentially directed outlet;

(b) a blower rotatably mounted in said housing;

(c) a plate covering said inlet and including a central boss directed toward said inlet, said boss having a concave curved annular surface forming a wall essentially equally distant from the curved margins of said inlet opening; 4

(d) said plate extending radially beyond the diameter of said inlet and spaced from said housing to form therewith an annular passage, to cause radially inward flow of air to said boss for diversion into said inlet;

(e) and a heating element distributed in said passage, whereby air in flowing radially inward through said passage traverses said heating element to extract heat therefrom.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 10/48 Great Britain.

RICHARD M. WOOD, Primary Examiner, ANTHONY BARTIS, Examiner, 

